Basic Qualification · B-007 Radio wave propagation · B-007-005-010
The ability of the ionosphere to refract high frequency radio signals depends on:
- A the power of the transmitted signal
- B the receiver sensitivity
- C upper atmosphere weather conditions
- D the amount of solar radiation
Correct answer: D — the amount of solar radiation. From the official ISED question bank, verified word for word.
Why
The ionosphere acts like a mirror for high frequency signals, but it only forms when sunlight hits the upper atmosphere. The full explanation — and one for every question — is in Pro.
Practise this section
How signals travel: the ionosphere and its layers, skip, ground wave, sporadic E, and which bands work when.